The present invention relates to the technical field of terminal or interconnection blocks, which may or may not be modular, used to supply and control electrical plants.
In the above field, the invention more particularly relates to terminal blocks intended to accommodate one or more plug-in connectors.
Such terminal blocks generally comprise an insulating casing in which at least one housing for accommodating a plug-in connector is provided.
In order to prevent the inadvertent detachment of the terminal block from the connector due to the effect, for example, of vibration or else of forces exerted on the conductors connected to the connector, it has been proposed to implement means of locking the connector to the terminal block.
Thus, it has been proposed to provide, at the end of the connector intended to be engaged into the accommodating housing, a stop intended to cooperate with a complementary recess of the housing. The stop and its complementary recess effectively mike it possible to lock the connector onto the casing but, however, have the drawback of making it particularly difficult to remove the connector once the latter is connected to the terminal block. This is because, either the stop and its complementary recess are designed so that they do not offer very much resistance to the removal of the connector, in which case the locking function is not appropriately provided, or, on the other hand, the stop and its complementary recess are designed to offer considerable resistance to the removal of the connector, in which case the locking function is completely provided but it is virtually impossible to remove the connector without damaging the terminal block or the connector itself.
In order to overcome this drawback, it has been proposed to use a catching lug connected to the connector and intended to engage in a complementary stop of the terminal block, as a means of locking the connector to the terminal block. A lug of this sort is satisfactory in its function of locking the connector to the terminal block and, moreover, it allows easy unlocking when it is necessary to detach the connector from the terminal block.
However, the use of such a connected catching lug has the drawback of increasing the overall size of the connector. Furthermore, the connected lug catches on a stop provided in a side wall of the terminal block such that it is not possible to use such a catching lug for locking a connector plugged into a central region of the terminal block.
Moreover, since the catching lug is connected to the connector, it is necessary, when using the connector, to make provision for this catching lug which will increase the number of components needed to produce a junction and connection assembly. Furthermore, the catching lug has an overall size which makes it difficult to use in a cramped environment.
There therefore appears to be a need novel locking means which guard against the drawbacks above and which, especially, are simple to use and have a small overall size, while providing effective locking of the connector to the terminal block and with which there is no risk of loss.
In order to achieve these objectives, the invention relates to a terminal block which comprises
an insulating casing in which at least one housing for accommodating a connector, which can be plugged into the housing in a direction (D), is provided, and
means for locking the connector to the casing.
According to the invention, the terminal block is one in which the locking means comprise:
at least one locking arm which:
is secured to the casing,
swings around an axis of rotation (xcex94), between a withdrawal position and a locking position,
is equipped with a catching element intended to cooperate in the locking position with a complementary catching element of the connector, and
means for immobilizing the arm in the locking position.
Thus, since the locking arm is secured to the terminal block, it is not possible to lose it. Furthermore, this permanent presence prevents any risk of oversight during mounting and assembly of a junction and connection assembly using one or more terminal blocks according to the invention.
According to one feature of the invention, in order to reduce as much as possible the overall size of the terminal block and the space dedicated, on the latter, to the locking means, the axis of rotation xcex94 of the arm is substantially perpendicular to the plug-in direction D of the connector.
The locking arm may be produced in any suitable manner and, according to a preferred feature of the invention, the locking arm has an elongate shape with an axis d and bears, at one end, the catching element, and at the opposite end, means for articulating to the casing.
The articulation means may then be produced in any suitable manner, such as for example in the form of a bearing intended to cooperate with a spindle borne by the casing of the terminal block. Similarly, the interconnection means may also be produced in the form of a spindle secured to the locking arm and intended to engage in a bearing provided on the insulating casing of the terminal block.
According to a preferred embodiment of the invention, the means of immobilizing the locking arm comprise a stop provided on the casing in order to support the arm in the locking position and to obstruct the passage of the arm into the withdrawal position from this locking position.
In a preferred embodiment of the invention, the locking arm then has, at its articulation end and away from the catching element, a heel intended to bear on the stop of the caning when the arm is in the locking position.
In order to offer high resistance to unlocking, especially under the effect of forces applied to the catching element by the locked connector, the heel is located opposite the housing accommodating the connector with respect to the axis xcex94 of rotation of the arm.
According to another feature of the invention, the immobilizing means comprise a rack provided on the casing and at least one tooth borne by the locking arm and intended to cooperate with the rack to impede the movement of the locking arm between its withdrawal position and its locking position, and vice versa. In a preferred, but not strictly necessary, manner, the rack is used in combination with the immobilizing stop provided on the casing.
According to the invention, the catching element of the locking arm can be provided in any suitable way, such as for example, in the form of a male or female catching element intended to cooperate with an element of complementary shape provided on the connector. According to a preferred embodiment, the catching element consists of a finger intended to cooperate with a stop offered by the connector to obstruct the removal of the connector from the accommodating housing. In a preferred, but not strictly necessary, manner, the stop of the connector consists of the edge of a cavity for accommodating the catching finger provided in the outer wall of the connector.
Moreover, according to a preferred, but not strictly necessary, embodiment, the arm has a cavity for accommodating an external maneuvering member, in order to facilitate the manipulation of the arm between the locking position and the withdrawal position and vice versa. In a preferred manner, this maneuvering cavity is provided at the end of the arm opposite the articulation end on the casing and has a shape suitable for accommodating the end of a screwdriver blade. Thus, when it is necessary to unlock the arm, it is possible to have available, by inserting the blade of a screwdriver into the maneuvering cavity, an arm with a considerable lever effect.
According to another feature of the invention, the locking arm has linking means intended to link the locking arm with another locking arm of an adjacent linking block.
The linking means may be provided in any suitable way, and, according to a preferred, but not strictly necessary, embodiment of the invention, the linking means comprise a peg provided on one side face of the arm, and a recess with a shape complementary to that of the peg, provided on the opposite side face of the locking arm.
The invention also relates to an assembly of at least two juxtaposed terminal blocks according to the invention. This assembly is one in which the locking arms of at least two adjacent terminal blocks are linked to each other.
This link may then result from using linking means as mentioned above and can therefore be dismantled. The link of the locking arm for adjacent blocks may also result from manufacturing the locking arms of two adjacent blocks as a single part. The production of the locking arms of more than two blocks, as a single part, may also be provided. Of course, this embodiment does not exclude the possibility of involving linking means which can be dismantled, provided in the side faces of the part constituting the juxtaposed linking arms.